The devastating 2004 Indonesian tsunami, with its death toll of as many as 250,000 people, was caused by the first magnitude-9.0 earthquake since 1967. A succession of destructive tremors in Haiti, Chile, and New Zealand - surpassed by this year's magnitude-9.0 quake in Japan - has some researchers wondering whether the number of large earthquakes is on the rise. The biggest quake ever recorded was the magnitude-9.5 Chile earthquake of 1960. It accounts for about a quarter of the total seismic strain released worldwide since 1900. The recent quake in Japan unleashed one-twentieth of that global total, In just three minutes. The Indonesian quake "reinvigorated interest in these giants," says the president of the Seismological Society of America. The Chile and Japan earthquakes - along with a magnitude-9.2 quake in Alaska in 1964 - triggered catastrophic tsunamis.
Records from the past century reveal some periods that have seen an unusual number of giant earthquakes, defined as those with magnitude 8.0 or higher. For example, global seismic data show a dramatic spike in the rate of large earthquakes from 1950-67. But there have also been quiet periods with fewer large quakes. And with only 100 years worth of records to consult, researchers aren't sure what these patterns of large quakes might mean -- or whether they mean anything at all. Even if clusters of giant earthquakes are a real phenomenon, researchers don't have any good ideas on how one big quake can trigger another big one in a different part of the world.
Further evidence against the significance of apparent clustering came in a recent study which found that large earthquakes do not generate other large quakes on a global scale. The RARITY of large earthquakes means that questions about possible connections between them are difficult to answer. "We see magnitude-7 earthquakes only 15 or so times a year and magnitude-9 earthquakes only a few times a century." Until researchers know more about why the rate of large earthquakes varies over time "we shouldn't be worrying less, but there's no need for panic either."
The recent spate of giant earthquakes may not signal more to come, but "it's undeniable that we're becoming more and more vulnerable to the effects of earthquakes in general." Many rapidly growing cities around the world aren't prepared for a large quake, while at the same time coastal communities are expanding into tsunami-prone areas. "We just have more people in precarious places."
I would only believe in a God who knew how to dance.**
Friedrich Nietzsche
LARGEST QUAKES -
This morning -
5.4 SOUTH OF FIJI ISLANDS
5.2 WESTERN SICHUAN, CHINA
5.0 KERMADEC ISLANDS REGION
Yesterday -
4/9/11 -
6.0 KYUSHU, JAPAN
5.3 NEAR EAST COAST OF HONSHU, JAPAN
5.4 OFF EAST COAST OF HONSHU, JAPAN
4/8/11 -
5.3 KURIL ISLANDS
5.1 MINDORO, PHILIPPINES
5.0 BANDA SEA
5.0 NEAR EAST COAST OF HONSHU, JAPAN
Pair of magnitude-3.9 quakes rumble central Arkansas - The US Geological Survey says the latest big quake struck near Greenbrier on Friday, less than 24 hours after an equally strong quake hit nearby. Officials said no one was hurt and damage was minimal. The quakes are the largest in the area since two natural gas companies agreed to close a pair of nearby injection wells last month.
Earthquakes Continue Near Greenbrier, Arkansas on Thursday - For about seven days, only one earthquake had struck, but then on Thursday five earthquakes above magnitude 2.5 hit.
MYSTERY BOOMS -
CANADA - 4/7/11 - Mysterious Rumbling has local residents baffled. Ontario's Environment Ministry is investigating reports of mysterious rumblings in parts of Windsor and Essex County [across the border from Detroit, Michigan]. Nine formal complaints have been registered to the local ministry office and there have been numerous telephone inquiries. "I feel like I'm going mental," said a resident. "It's in the ground and it feels like there is a subway under the house. It happens at all different times - in the middle of the night, as well."
The ministry has investigated underground blasting at the Windsor Salt mine, but the company blasts only once a day Monday to Friday in midafternoon. "We just want to know what the noise is. It's just weird that nobody knows. If it's not the salt mines, then what is it?" Ministry of Environment officers have asked homeowners to keep a log in order to help find the source of the rumbling.
The calls about the noise have come from nearly every corner in Windsor and the surrounding area. The ministry's goal is to eliminate any possibility the vibrations are being caused by an industrial source on either side of the border. Mining activities by salt companies on either side of the border have been ruled out because "their operations are not coinciding with the times people are feeling these (vibrations)."
Another possibility could be overhead jets circling, landing and taking off from Detroit Metropolitan Airport, but that's not believed to be the case. "The vibrations definitely are more underground. All I hear is the rumbling." "It's a mystery. There appears to be no rhyme or reason to it."
VOLCANOES -
Philippine Taal volcano alert level raised - Magma rising to the surface of the volcano on a popular island close to Manila has prompted the Philippine government to push up its alert level and urge visitors to stay away. The second stage of a five-step alert system has been imposed around Taal Volcano after increased signs of activity were detected.
While this does not mean an eruption is imminent, on Saturday tourists and residents were warned to steer clear of Taal's crater and from thermal vents on its northern side. "It is still a grey area, we still cannot say if it will culminate in an eruption." The volcano could suffer intensified activity but could also slowly subside as it did last year after showing increasing activity in June. Taal is one of the most unstable of the country's 22 known active volcanoes with 33 recorded eruptions, the last one in 1977.A lake surrounding the crater prevented deaths in 1977 and during other eruptions, as the body of water protected outlying areas from the lava.
Taal Volcano rocked nine times Friday while Mt. Bulusan had three earthquakes in 24 hours.
TSUNAMI / FREAK WAVES / ABNORMAL TIDES -
The Man Who Predicted the Tsunami - After studying ancient rocks, a Japanese geologist warned that a disaster was imminent — to no avail. The giant tsunami that assaulted northern Japan's coast surprised just about everyone. But Masanobu Shishikura was expecting it. "It was the phenomenon just as I had envisioned it," says the geologist, who has now become the Japanese Cassandra.
Dr. Shishikura's studies of ancient earth layers persuaded him that every 450 to 800 years, colliding plates in the Pacific triggered waves that devastated areas around the modern city of Sendai, in Miyagi Prefecture, as well as in Fukushima Prefecture. One early tsunami was known to historians. Caused by the 869 Jogan quake, its waves, according to one chronicle, killed 1,000 people. Dr. Shishikura had found strong evidence of a later tsunami in the same region, which probably took place between 1300 and 1600. "We cannot deny the possibility that [such a tsunami] will occur again in the near future," he and colleagues wrote in August 2010. He was beginning to spread the word. Plans were under way at his center to hand out maps so people would understand which areas were at risk. Dr. Shishikura had an appointment on March 23 to explain his research to officials in Fukushima. Dr. Shishikura's boss at the center had even mentioned the results at a 2009 meeting of an official committee discussing the safety of nuclear-power plants. But the idea of beefing up tsunami preparedness didn't go anywhere.
His work is part of a young field called paleoseismology. Kerry Sieh, a pioneer in the specialty, says that the few dozen people who do this kind of work are usually doomed to be ignored. Humans are made to trust what they have seen themselves, or what someone they know has seen. They aren't designed "to deal with these once-in-500-year events."
Many lives could have been saved, at relatively little cost, by spreading awareness of the danger. People in Miyagi and Fukushima prefectures were used to strong quakes, but the location and magnitude of these seismic events didn't generate tsunamis. Further north on the eastern coast, tsunamis were well-known from quakes in 1896 and 1933. Those were of yet another, weaker variety that affected mainly low-lying areas along the coast. During the magnitude 9.0 quake on March 11, some people well inland, thinking themselves safe, took time to change clothes or to make phone calls. Others watched the disaster unfold instead of running to high ground. They proved what Dr. Shishikura's group wrote last year about local tsunamis: "It appears to be almost completely unknown among the general public that in the past great tsunamis have inundated areas as far as 3-4 kilometers inland as the result of earthquakes exceeding magnitude 8."
Now, Dr. Shishikura's team is looking at the Nankai trough to the south, which could trigger tsunamis hitting the island of Shikoku and the Kii Peninsula. Large tsunamis appear to hit there every 400 to 600 years, with the most recent in 1707. Those rough calculations suggest the danger is at least a century away. Still, "we had better be on the lookout."
Hawaii will absorb brunt of Japan earthquake debris - An analysis by scientists shows that the vast swath of detritus will reach island shores in the next two years. It will take years, but Hawaii ultimately will bear a heavy burden from floating debris from the March 11 tsunami in Japan, Hawaii researchers conclude. Projections based on drifting buoys lead the researchers to estimate that the flotsam will reach the ecologically sensitive Northwestern Hawaiian Islands within a year, brush the rest of Hawaii in two years and hit the West Coast in three years. From there, the debris will drift into the so-called Great Pacific Garbage Patch, northeast of Hawaii, where it will circulate and break into smaller pieces. As storms, eddies and the effects of El Nino push the pieces out of the patch, they will head toward Hawaii. Some will go toward Hawaiian beaches, and other parts will slip between islands and return to the garbage patch, to return the next time. It is safe to say after five years Hawaii will be the main coastline impacted by this debris.
Some of the debris will sink or deteriorate as it moves eastward on the North Pacific gyre, a vast clockwise circulation pattern. California is protected to some degree by coastal upwelling, but some significant amounts will end up on the Washington coast, British Columbia and Alaska. Some will also reach Mexico. (map)
TROPICAL STORMS -
No current tropical storms.
SEVERE RAIN STORMS, FLOODING, LANDSLIDES -
GERMANY - At least eight people were killed and 130 injured as a FREAK sandstorm caused a massive pile up in Germany's east. At least 21 people were still in hospital as a result of yesteray's massive pile-up. Sand and dirt were blown on to the four-lane A19 near Rostock, close to the Baltic Sea in Mecklenburg-Western Pomerania state, on Friday. The pile-up involved 80 cars and three lorries, with 20 vehicles set ablaze. A combination of recent dry weather, ploughing of fields and high winds was blamed for the accident. At least 41 people were hurt. Many suffered serious injuries and there are fears the death toll could rise.
One motorist told reporters that "all of a sudden, there was a black wall of sand and then I couldn't see anything any more and I was pushed into another car. I have never seen anything like it before and it's difficult to describe. I think I will only later realise what happened. I think this is my second birthday today."
All of the fatalities appear to have occurred on the northbound carriageway. One of the lorries involved there was carrying inflammable material and sparked several fires. About 30 vehicles crashed on the southbound carriageway. The road was closed in both directions as rescue work continued. (photo & map)
EXTREME HEAT & DROUGHT / WILDFIRES / CLIMATE CHANGE -
Fire could be WORST IN TEXAS HISTORY - Texas Forest Service officials today braced for what could be one of the worst days in the state's history for battling wildfires. Relentless heavy winds and dry weather could even spawn a rash of wildfires similar to those that swept across the southern plains states on April 9, 2009. Those fires scorched 147,924 acres, destroyed 111 homes and killed four people. Strong winds whipped up wildfires across north and west Texas Saturday. On Saturday, they battled 18 fires, the largest of which was the Swenson Fire, located in northern Texas. That blaze burned some 61,500 acres and destroyed at least one home. As of late Saturday, the blaze had not been contained.
The National Weather Service, citing strong winds and relatively low humidity, has issued a red flag warning for the western parts of Texas, Oklahoma and Kansas. Elsewhere in the U.S. southwest, a grass fire burning just south of Cleveland, Oklahoma prompted evacuations on Saturday. As many as 70 firefighters were involved in the response, as well as three helicopters. Twelve families checked into a Red Cross shelter, but more were evacuated.
Drought intensifies in Texas with DRIEST MARCH EVER March's paltry precipitation, far below the normal 3.06 inches in North Texas, puts the region about 10 inches below normal since Tropical Storm Hermine dumped more than 6 inches of rain — and spun up a couple of tornadoes — in early September.
